<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <!-- <div class="main">
        <div class="header"></div>
        <div class="menu"></div>
        <div class="section"></div>
    </div> -->
    <!-- <section>
        <header></header>
        <aside></aside>
        <article></article>
    </section> -->
    <p>
        <label for="username">
            用户名:<input type="text" name="" id="username">
        </label>
    </p>
    <p>
        <label for="nan">
            <input type="radio" name="sex" value="男" id="nan">男
        </label>
        <label for="nv">
            <input type="radio" name="sex" value="女" id="nv" checked>女
        </label>
    </p>
</body>
</html>